mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-11 22:00:08 +00:00
9fc813e1a3
This will be used to consolidate the libgcc_s access for backtrace and pthread_cancel. Unlike the existing backtrace implementations, it provides some hardening based on pointer mangling. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
75 lines
2.4 KiB
C
75 lines
2.4 KiB
C
/* Dynamic loading of the libgcc unwinder. MIPS customization.
|
|
Copyright (C) 2020-2021 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _ARCH_UNWIND_LINK_H
|
|
#define _ARCH_UNWIND_LINK_H
|
|
|
|
#include <stdint.h>
|
|
#include <sys/syscall.h>
|
|
|
|
#define UNWIND_LINK_GETIP 1
|
|
#define UNWIND_LINK_FRAME_STATE_FOR 1
|
|
#define UNWIND_LINK_FRAME_ADJUSTMENT 1
|
|
#define UNWIND_LINK_EXTRA_FIELDS
|
|
#define UNWIND_LINK_EXTRA_INIT
|
|
|
|
/* MIPS fallback code handle a frame where its FDE can not be obtained
|
|
(for instance a signal frame) by reading the kernel allocated signal frame
|
|
and adding '2' to the value of 'sc_pc' [1]. The added value is used to
|
|
recognize an end of an EH region on mips16 [2].
|
|
|
|
The idea here is to adjust the obtained signal frame ADDR value and remove
|
|
the libgcc added value by checking if the previous frame is a signal frame
|
|
one.
|
|
|
|
[1] libgcc/config/mips/linux-unwind.h from gcc code.
|
|
[2] gcc/config/mips/mips.h from gcc code. */
|
|
|
|
static inline void *
|
|
unwind_arch_adjustment (void *prev, void *addr)
|
|
{
|
|
uint32_t *pc = (uint32_t *) prev;
|
|
|
|
if (pc == NULL)
|
|
return addr;
|
|
|
|
/* For MIPS16 or microMIPS frame libgcc makes no adjustment. */
|
|
if ((uintptr_t) pc & 0x3)
|
|
return addr;
|
|
|
|
/* The vDSO containes either
|
|
|
|
24021061 li v0, 0x1061 (rt_sigreturn)
|
|
0000000c syscall
|
|
or
|
|
24021017 li v0, 0x1017 (sigreturn)
|
|
0000000c syscall */
|
|
if (pc[1] != 0x0000000c)
|
|
return addr;
|
|
#if _MIPS_SIM == _ABIO32
|
|
if (pc[0] == (0x24020000 | __NR_sigreturn))
|
|
return (void *) ((uintptr_t) addr - 2);
|
|
#endif
|
|
if (pc[0] == (0x24020000 | __NR_rt_sigreturn))
|
|
return (void *) ((uintptr_t) addr - 2);
|
|
|
|
return addr;
|
|
}
|
|
|
|
#endif /* _ARCH_UNWIND_LINK_H */
|